The long-term objective of this research is to expand understanding of the developmental course of depression among married adults. Specifically, the aims of this research are to examine how depressive symptoms change overtime, paying particular attention to potential gender differences in depression. Moreover, this research uniquely considers how husbands' and wives' symptoms influence the developmental course of their spouses' mental health problems, as well as the role of marital functioning on couples' depressive symptoms. This research is directly aligned with NIMH's goal of reducing the burden of mental illness by providing an in-depth longitudinal examination of the processes underlying depression, which is critical for informing therapeutic approaches for depression. Furthermore, given findings that men are less likely to seek treatment for mental illness and the limited empirical research on depression among men, this research has implications for the development of alternative forms of therapy better tailored toward men. Data for this project comes from a prospective longitudinal study of 297 married couples. Each year, husbands and wives completed questionnaires about their own depressive symptoms and marital functioning and were videotaped discussing an everyday topic of disagreement. Latent difference score analyses using structural equation modeling will be employed to examine the developmental course of depression, the dynamic interplay among husbands' and wives' depressive symptoms, and how changes in marital functioning are related to changes in mental health symptoms. This research is of great relevance to public health. Depression is one of the most prevalent mental health problems in America, yet there is a gap in our understanding of how and why depressive symptoms develop and are maintained. The proposed research addresses this gap by examining how symptoms unfold and change over time among married adults, as well as expands current understanding of depression by examining possible mechanisms (e.g., quality of marital relationship) underlying depressive symptoms. This research is essential in order to tailor existing and develop new therapies for the treatment and prevention of depression, thereby alleviating the burden associated with experiencing depressive symptoms and its cost to families and societies. [unreadable] [unreadable] [unreadable]